Cell-based cancer immunotherapy is a method of treating cancer that uses immune active cells, including dendritic cells (DCs). Because DCs cannot be harvested in sufficient numbers otherwise, they are typically generated by the differentiation of monocytes extracted from peripheral blood. However, generating clinically relevant numbers of monocyte-derived dendritic cells for therapeutic use can be challenging. Conventional generation techniques, such as standard well plate and T-flask culture, involve a cumbersome process with many manual steps that expose the cell culture to the outside environment and require a highly trained technician.
The conventional generation techniques have numerous safety and contamination concerns, such as patient sample mix-up and misidentification, exposure to unknown contaminants inside the laminar flow hood (e.g., particulates and bacteria/fungus resistant to standard sterilization techniques such as 70% ethanol), and accidental exposure of culture to a septic environment. Furthermore, scale-up of manual DC generation techniques is generally not feasible aside from adding more culture vessels to the workflow. Automated systems that continuously perfuse fresh medium into a culture vessel while simultaneously removing depleted medium are an alternative to conventional, manual generation techniques.
Though automated systems generally have fewer safety and contamination concerns than conventional techniques, the automated systems suffer from scale-up and other issues. For example, many commercially available automated systems are not scalable for research or clinical-level production of DCs. Also, automated systems suffer from non-uniform flow, or dead spots in flow, within the cell culture vessel. Dead spots in flow (dead areas) are areas in the cell culture vessel that do not maintain uniform flow when fresh medium is provided and depleted medium is removed, thereby affecting generation of the DCs.